title: The macular pigment optical density spatial profile and increasing age.
abstract: OBJECTIVE
  To investigate the relationship between the central spatial profile of macular pigment optical density (MPOD) and increasing age in normal eyes.
  
  
  METHODS
  Ninety-eight individuals (aged 19-71 years) with good visual acuity, free from ocular disease, and with clear ocular media participated. MPOD was measured at 0.25, 0.50, 1.00, and 1.75° eccentricity from the foveal centre using a heterochromatic flicker photometry based densitometer instrument.
  
  
  RESULTS
  Linear regression analysis revealed that there was no statistically significant association between MPOD and increasing age for the group as a whole at 0.25, 0.50, and 1.00° eccentricity (p > 0.05 for all eccentricities). There was a small but statistically significant positive association between increasing age and MPOD at 1.75° eccentricity (p = 0.020), but age only accounted for 6 % of the variation in MPOD values. Fifteen percent of all participants had a non-exponential MPOD spatial profile.
  
  
  CONCLUSIONS
  There was no statistically significant relationship between MPOD and increasing age for three of the four locations measured. A significant proportion of individuals show an atypical MPOD spatial profile, indicating that studies on MPOD should ideally report information on the MPOD spatial profile rather than estimates from only one retinal location.
authors.affiliation: Vision Science Research Group, School of Biomedical Sciences, University of Ulster, Coleraine, BT52 1SA, Northern Ireland, UK, r.beirne@ulster.ac.uk.
authors.forename: Raymond O
authors.initials: RO
authors.lastname: Beirne
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D003720:Densitometry; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D014975:Lutein / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010783:Photometry / Q000379:methods; D012160:Retina / Q000378:metabolism*; D012168:Retinal Pigments / Q000378:metabolism*; D024341:Xanthophylls / Q000378:metabolism*; D055815:Young Adult; D065146:Zeaxanthins
chemical_list: D012168:Retinal Pigments; D024341:Xanthophylls; D065146:Zeaxanthins; D014975:Lutein